The ability to increase the storage capacity of magnetic recording media is an ongoing concern. As the bit areal densities of magnetic recording media continue to progress in an effort to increase the storage capacity of hard disc drives, the physical size of the sensors and writers designed to read and write data from and to the magnetic recording media must correspondingly decrease. Accordingly, the stripe width (SW) and stripe height (SH) of the read sensors, which define the physical size of the read sensors, must decrease in order to achieve the higher areal densities. As a result of this push to increase the storage capacity of hard disc drives, read and write sensor critical dimensions are being pushed below the 100 nm scale.
Scaling the stripe widths of currently manufactured read heads estimates that a stripe width of approximately 25–35 nm is required to achieve an areal density of approximately 1 Tbits/in2. Scaling past reader stripe height designs for previous products (e.g., current-in-plane spin-valve sensors) estimates that a stripe height of approximately 15–30 nm is required for an areal density of approximately 1 Tbits/in2. Manufacturing a read sensor along the anticipated dimensions is a difficult task utilizing current processing technology.
The sensor width, or stripe width, is currently defined via lithography (DUV, e-beam, etc.) and etching (Ar ion milling, reactive ion beam etching, reactive ion etching, etc.). Now that the data storage industry is passing the semiconductor industry in the minimum critical dimensions needed for read and write sensors, it is becoming more difficult to shrink the width and height of the sensors and control the variation of sensor width and height from sensor-to-sensor and wafer-to-wafer. Once a sensor is etched, there is currently no way of reworking, adjusting or tuning the sensor, or stripe, width. Additionally, the sensor height, or stripe height, is typically defined using a mechanical lapping process and electronic lapping guides (ELGs) to set the stripe height. Once the sensor is lapped, there is currently no way of reworking, adjusting or tuning the sensor, or stripe, height. If the head was lapped or etched improperly, the head needs to be scrapped.
The present invention is directed towards overcoming one or more of the above-mentioned problems.